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Re: RS6000 fix pr16480


>>>>> Alan Modra writes:

Alan> I should have made it clear in my patch submission:  I didn't just
Alan> simply remove the abort to work around a problem.  Instead, I looked at
Alan> all the types of address that rs6000_legitimate_address allows.  The
Alan> REG_P test is necessary, and I think the rs6000_split_multireg_move code
Alan> now will handle all the addresses that it needs to.  (*)

	I think we're not communicating.  I was not suggesting that the
removal of abort was gratuitous.

	My question is whether it truly is okay to follow the codepath
that you changed and leave j=-1.  Other paths leave j=-1, but the path you
changed used to assert that it had discovered a REG and would set j or it
had not found a REG and would abort.

	As far as I can understand, this would mean that SRC is

(mem (symbol_ref))  or  (mem (const (plus (symbol_ref) (const_int))))

and DST is a GPR.

	So you patch changes the behavior for LO_SUM, SYMBOL_REF, and
CONST, which previously would have aborted.  Now it sets j for the former
and leaves j=-1 for the latter two.

	I was not sure from the patch if that is what you intended.

Thanks, David


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